上海海滨三带喙库蚊和中华按蚊消失情况分析

Analysis of Disappearance of Culex Tritaeniorhynchus and Anopheles Sinensis in Coastal Area of Shanghai

本文报道了1982～1990年8年间三带喙库蚊在上海海滨猪圈秋季和冬季消失情况。该蚊9月下旬成虫密度下降明显,且出现突减现象,11月消失。中华按蚊无消失现象。对三带喙库蚊消失期间偶然出现的二个特例,经气象分析,认为也符合迁飞昆虫北迁降落的规律。最后还探讨了三带喙库蚊滞育后回迁南方过冬的可能性。

This paper reports on the result of 8-year (1982~1990) observation of the autumn flucuat- ion and the winter disappearance of Culex trit- aeniorhynchus (Cx. tri.) in pigsties in the coa- stal area of Shanghai. The density of Cx. tri. decreases remarkably in late September and a sudden decrease of unparous mosquitoes could be seen as well. From November on the densi- ty of Cx. tri. gradually decreases along with the frequent hit of cold air until disappearance. During the previous 8 years, the shortest disa- ppearance period was 85 days; while the longest was 144 days; the average was 110 days. No disappearance phenomena occurred for Anophe- les sinensis. However, even during the period of disappearance of Cx. tri., it was still possi- ble to trap Anopheles sinensis so long as the daily maximum temperature is above 10℃.Ato- tal number of 532 Anopheles sinensis were ca- ptured in syear. Among them the parous mo- squitoes took 14.7%. Only a few Cx. tri. were occasionally captured during the period of disa- ppearance in particular years. For example, 6 and 1 mosquitoes were captured with ultravio- let light trap respectively in February 11, 1987 and February 22, 1988. However, Meteorologic- al analyses showed that the appearance of Cx. tri. in winter still conformed to the northward migration pattern of the migratory insects. Fi- nally, the possibility of southward migratory flying of Cx. tri. after the diapause for over- wintering was discussed.